Paclitaxel is a generic name used by generic pharmaceutical producers, such as the Israeli company Teva. It is extracted from Yew tree bark and purified through various solvent extraction / crystallisation steps.
Paclitaxel is a natural product with antitumor activity. It is sold under the registered tradename TAXOL® by the Bristol Myers-Squibb company as a semi-synthetic chemotherapy drug, processed from Taxus baccata (Yew). See http://www.bms.com/products/data/index.html